244 THE CANADIAN ENTOMOLOGIST. 



Urocerus ripar-ius, sp. nov. 



Black ; clypeus, labrum, mandibles except at tip, spot behind the 

 eye, joints 3-9 of the antennae, prothorax, apex of the front and middle 

 femora, their tibiae and tarsi, the base of the hind tibia and metatarsus, 

 the two apical segments of their tarsi, and abdominal segments three to 

 six, yellow ; antennae twenty- one-jointed, the yellow band on the antennae 

 is clouded with fuscous and varies in width; wings yellow, slightly 

 clouded, veins black. Length, 22 mm. ; alar expanse, 33 mm. Two 

 males, one from Skokomish River, May 3. 



DESCRIPTIONS OF THE LARV.E OF CERTAIN 



TENTHREDINID^E. 



BY HARRISON G. DYAR, NkW YORK. 



Hemichroa americana, Provancher. 

 (The alder saw-fly). 



Described as a Dineura, but the lanceolate cell is contracted in the 

 middle, not petiolate. The second recurrent nervure is received very 

 near the end of the second submarginal cell, almost at the intersection of 

 second and third submarginal cells. 



$ . — Shining black, the legs brownish-yellow, all the coxae, the apical 

 third of posterior tibiae and posterior tarsi black. Wings smoky, but 

 iiyaline along the outer margin. Nervures and stigma black. 



$ . — Head and body yellowish-brown ; antennae, eyes, metathorax 

 and legs as in the $ , black, or all the femora more or less black. Black 

 markings somewhat variable. 



A smoky spot in the centre of the second submarginal cell in both 

 sexes. 



1 5 $ 6 > 8 $ $ . — Bred from larvae on Alnus serrulata, at Woods' 

 Holl., Mass., and Rhinebeck, N.Y. 



Eggs. — Laid in saw cuts opening below on the petiole and base of 

 midrib of a leaf. The cuts are in one or two rows, along one or both 

 sides of the rib, nearly contiguous. 



First stage. — Eating a little hole or slit through the leaf. Head 

 rounded, higher than wide, pale brown, eye black ; width, 0.3 mm. 

 Body curved into an S shape outside of the hole in the leaf, through 

 which the larva readily moves. Translucent honey-yellow, annulate, 

 scarcely shining ; the alimentary canal gives a greenish tinge by trans- 

 parency. 



